This invention was made with government support under contract number DE-AC06-76RLO 1830, awarded by the U.S. Department of Energy. The government has certain rights in the invention.
The disposal of contaminated material has become an increasingly significant problem. Today, contaminated material, such as industrial and nuclear waste, is buried underground in specially designed storage containers. These contaminants buried in the ground typically contain volatile, semi-volatile, and non-volatile organic contaminants. Unfortunately, burying the contaminants does not render them unharmful to the environment. The storage containers can leak the contaminants into the soil, thereby polluting the soil. The contaminates may also pass into underground water tables and contaminate the water supply for populated regions. Ground contaminates can also result from surface spills that seep into the soil.
One approach to detoxifying organic-contaminated soils was proposed by Buelt et al. in U.S. Pat. No. 4,957,393, assigned to Battelle Memorial Institute. Buelt et al. proposed inserting a matrix of electrodes into a contaminated soil region and applying very high DC voltage or single phase AC voltage to the electrodes. The voltages created current paths between the electrodes which effectively heated the contaminated soil to temperatures ranging from 100.degree. C. to 1200.degree. C.
The present invention arose out of a need to provide a more energy efficient and less costly system for treating contaminated soils. The present invention provides a method for treating contaminated soil which enables uniform heating of the soil at relatively low energy costs.